I think that the concept of the sim card is out of date nowadays and I would advocate getting rid of them completely. Up until a year or so ago, this wasn't so important, but now we have so many devices - tablets, cameras, even smartwatches that can be used with a sim card, I think now's the time to get rid of them completely. I have a few devices now that take sim cards and the process of changing sim cards between devices, or even buying separate sim cards to use in each device separately, seems very old fashioned and inconvenient. What I would suggest is some kind of system that would do away with the need for sims altogether. Perhaps an app that could be installed on the device, where the user can input the simcard number in order to get access to the network. Of course this would need to be secure, but there could be prompts for the user to have to answer a security question, or even to make a call to the network operator to register the device. Depending on your contract or plan, the network could allow 2,3 or maybe 4 devices per 'sim'. The app could allow you to control which device can send/receive phone calls or SMS, with data access being possible on all devices, with data usage being combined. What do you think of this idea? I'm sure it's possible to happen but I doubt that it will. Perhaps there's some flaw that I haven't thought of?